s man in the middle kofi annan is is taking a break. first as secretary-general and most recently as special envoy to syria, he has entered some of the world's most difficult problems. now in an interview in geneva, kofi annan looks back. >> it is an honor... reporter: he is one of the most well known players on the world stage, respected for his unwaiverring commitment to international diplomacy but also fiercely criticized for failing to stop the bloodshed in rwanda, bosnia, and most recently in syria. in his new book former u.n. secretary general kofi annan attempts to shape how history will remember his 40 years at the united nations. >> well, i hope that it will be said that he made a contribution. >> reporter: his name will forever be attached to some of the darkest chapters in the u.n. history. he was the head of u.n. peace keeping forces when some 800,000 people were killed in rwanda. the next year more than 8,000 bosnian men and boys were slaughtered in a place designated a so-called u.n. safe area. you said with regards to rwa